Surgical cord tensioning devices, systems, and methods

ABSTRACT

A system, a method, and instruments for manipulating a surgical cord into spinal implants to assist in correcting a spinal deformity are described. The system may include a tensioner, a tensioner extension, and a counter tensioner. One of the instruments can include an elongate body, a dual coupler, and a nose member. The elongate body has a flexible cylindrical member adapted to carry tension along a longitudinal axis, where the flexible cylindrical member is sized to receive a surgical cord through a lumen within the flexible cylindrical member. The dual coupler is disposed on a proximal end of the elongate body, and include a bore for receiving a nose portion of a tensioner and for guiding the surgical cord into the tensioner. The nose member is disposed on a distal end of the elongate body, and be adapted to discharge the surgical cord from the elongate body.

BACKGROUND

Dynamic stabilization techniques, such as vertebral body tethering, areused in spinal treatment procedures for juveniles to permit enhancedmobility of the spine while also providing sufficient counter loading ofa spinal curvature to effect treatment through bone growth modulation,particularly during times of rapid growth. Such dynamic stabilizationsystems may include pedicle screws installed in adjacent or nearbyvertebrae of the spine and a flexible cord secured to the heads of thepedicle screws by set screws, with the cord under tension betweenpedicle screws.

SUMMARY

The present inventors have recognized, among other things, thatimproving ergonomics and ease of use of surgical cord (tether)tensioning devices, including improving access to remote implants, maybe desirable. The present inventors have also recognized that decreasingthe time to tension and secure the surgical cord in each implant canimprove outcomes and decrease surgeon fatigue. The present specificationdiscloses various methods, devices, systems, and embodiments that mayinclude a cord tensioner that can be rigidly, removably coupleable to acoupler disposed on a proximal end of a counter tensioner, wherein thedistal end of the counter tensioner can be rigidly, removably coupleableto a head of an implant. Additionally, the present specificationdiscloses various tensioner extensions that can be used to position andtension a surgical cord (tether) from an auxiliary or secondary incisionoffset (usually inferiorly) from the spinal deformity being corrected.Accordingly, the present disclosure provides for a system forpositioning and tensioning the surgical cord (tether) without repeatedthreading the cord through various surgical ports (incisions). Thesystem may comprise a tensioner, a tensioner extension, and a countertensioner. The tensioner can comprise a nose assembly and a cord lockassembly for applying tension to the cord. The nose assembly cancomprise a piston having a lumen extending therethrough for receivingthe cord and a spring positionable in contact with an indicator regionof the piston. The tensioner extension can include one or more elongateextension members that can accommodate the cord through an internallumen and couple to the nose of the tensioner. The counter tensioner canbe releasably coupleable to a head of an implant at a distal end thereofand can guide a set screw into the implant to secure the cord. Thecounter tensioner may also enable translation of the implant relative toanother implant implanted in an adjacent or nearby vertebrae. Further,the counter tensioner can be utilized as described in co-pendingapplication Ser. No. 16/115,441, Titled “SURGICAL CORD TENSIONINGDEVICES, SYSTEMS, AND METHOD,” filed Aug. 28, 2018, which is herebyincorporated by reference in its entirety.

In an embodiment, the present disclosure discusses a method forpositioning and tensioning a surgical cord using a secondary (auxiliary)surgical port and a tensioner extension threaded over the cord. In thisembodiment, the cord is initially secured in a first implant with thecord subsequently routed through the body to the secondary surgicalport. The cord is then threaded through the tensioner extension, and thetensioner extension is maneuvered into the body adjacent to a secondimplant. The tensioner extension, in combination with the countertensioner or other instruments, is used to position the cord in thesecond implant. Once in the second implant, the tensioner can be coupledto the proximal end of the tensioner extension, and utilized to tensionthe cord between the first implant and the second implant. Oncetensioned, the cord can be secured with a set screw delivered throughthe counter tensioner instrument Upon completion of securing the cord tothe second implant, the tensioner extension can maneuver the cord into athird implant and repeat steps to tension and secure the cord in thethird implant. This process can be repeated for all implants being usedto correct the spinal deformity.

In another embodiment, the present disclosure provides for a method thatcan include the steps of inserting a counter tensioner into a patientand coupling the counter tensioner to an implant; coupling a noseassembly of a tensioner to a port of the counter tensioner; guiding acord through the counter tensioner and securing the cord therein;tensioning the cord by actuating a shaft clutch to translate theelongate shaft and the cord; preventing proximal travel of the elongateshaft and cord via engagement of a shaft lock; and translating theimplant relative to an implant in an adjacent or nearby bone.

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 is a perspective view of an embodiment of a system according tothe present disclosure.

FIG. 2 is a cross-sectional view of one embodiment of a tensioneraccording to the present disclosure.

FIG. 3A is a perspective view of an embodiment of a counter tensioneraccording to the present disclosure and FIG. 3B is an exploded view ofthe counter tensioner of FIG. 3A.

FIG. 4A is a partial perspective view of an embodiment of a proximal endof the system in use in a first position and FIG. 4B is a partialperspective view of the distal end of the embodiment of FIG. 4A in use.

FIG. 5A is a partial perspective view of an embodiment of a proximal endof the system in use in a second position and FIG. 5B is a partialperspective view of the distal end of the embodiment of FIG. 5A in use.

FIG. 6 is a flow chart illustrating steps in one exemplary methodaccording to the present disclosure.

FIGS. 7A-7G illustrate a cord tensioning system, according to variousembodiments of the present disclosure.

FIG. 8A is a drawing illustrating a cord tensioning system operatingthrough an auxiliary surgical port, according to various embodiments ofthe present disclosure.

FIG. 8B is a drawing illustrating a cord tensioning instrument includinga tensioner extension and secondary extension, according to variousembodiments of the present disclosure.

FIGS. 9A-9E are drawings illustrating various aspects of a tensionerextension, according to various embodiments of the present disclosure.

FIGS. 10A-10F are drawings illustrating various aspects of a secondarytensioner extension, according to various embodiments of the presentdisclosure.

FIGS. 11A-11B are drawings illustrating a connection between a tensionerextension and a secondary tensioner extension, according to variousembodiments of the present disclosure.

FIG. 12 is a flowchart illustrating a surgical procedure for tensioninga surgical cord utilizing a tensioner, a tensioner extension, andoptionally a secondary extension, according to various embodiments ofthe present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments will now be described more fully with reference tothe accompanying drawings. Within the following disclosure the termsproximal and distal are generally used with reference to the surgeonusing the instruments, rather than with respect to the patient. However,in description of certain examples the use of the terms may be invertedto correspond to the patient point of view.

The initial portion of the present disclosure provides for a systemcomprising a cord tensioner that can be rigidly, removably coupleable toa port disposed on a proximal end of a counter tensioner, wherein thedistal end of the counter tensioner can be rigidly, removably coupleableto a head of an implant. Such systems and methods of using the systemcan improve ergonomics and ease of use by, e.g., enabling one handedoperation of a tensioner. Such systems can also increase cord travel peractuation cycle of the cord tensioner and provide a visual indication ofcord load during cord tensioning. FIGS. 1-7G address the systemcomprising only the cord tensioner and the counter tensioner. Theremaining portion of the disclosure discusses the system utilizing thetensioner extension to facilitate an improved method of securing asurgical cord (tether) between implants to correct a spinal deformity.

One exemplary embodiment of a system 100 according to the presentdisclosure is illustrated in FIGS. 1-3. The system 100 can comprise atensioner 102 and a counter tensioner 104, which are used in combinationfor manipulating implants 106 coupleable by a cord 108. The tensioner102 is designed to enable one-handed operation to apply tension to acord 108. The tensioner 102 can comprise a nose assembly 110 forreceiving the cord 108 and a cord lock assembly 112 for securing andapplying tension to the cord 108. The counter tensioner 104 can bereleasably coupleable to a head of an implant 106 at a distal end 114thereof and can have a port 118 disposed in a proximal end 116 thereof.The port 118 can be releasably coupleable the nose assembly 110 of thetensioner 102. The counter tensioner 104 can further be rigidlycoupleable to both the head of the implant 106 and the nose assembly110, allowing a surgeon to tension the cord 108 via the tensioner 102and translate the implant 106 and underlying vertebrae relative toanother implant implanted in an adjacent or nearby vertebrae via ahandle 130 in the same surgical step and as explained in greater detailbelow.

The implant 106 can be, for example and without limitation, a threadedfastener, a bone screw, a pedicle screw, a staple, a bone clamp, auniversal bone clamp, cam blocks, bone plates, and the like.Furthermore, it is contemplated that the tensioner can be used totension a cord between bones, clamps, or any implant secured to a bonein any manner. The implant 106 can comprise a shaft that purchasesunderlying bone and a head including features for securely engaging anelongate member that, prior to being secured, can be tensioned to applyforces to manipulate the position of adjacent or nearby vertebrae as ajuvenile patient experiences growth. The cord can be, for example andwithout limitation, any elongate member including a cord, a tether,strap, a cable, a wire, a suture, a thread, or similar flexibleligature. In additional or alternative embodiments, the elongate membercan have some beneficial temporal elastic properties that could, forexample and without limitation, avoid overcorrection or under correctionover the life of an implanted system, and the like. The term “cord” isused throughout the present disclosure, but should be understood toinclude any elongate member.

One exemplary embodiment of a tensioner 102 according to the presentdisclosure is illustrated in FIGS. 1-2. The tensioner 102 can comprise anose assembly 110 and a cord lock assembly 112 for applying tension tothe cord 108. The nose assembly 110 and the cord lock assembly 112 canbe at least partially disposed in the main body 124 of the tensioner 102

The cord lock assembly 112 can comprise a cord lock housing 208 disposedat a distal end of an elongate shaft 210 and can engage a cord 108therein. The cord lock housing 208 can comprise, for example and withoutlimitation, a cam cleat 212 or the like for engaging and disengaging thecord 108. The elongate shaft 210 can be operably coupled to a shaftclutch 214 to drive the elongate shaft 210 proximally and a shaft lock216 that can resist return of the elongate shaft 210 in the distaldirection at the end point of an actuation cycle of the tensioner 102.The shaft clutch 214 can extend from a first end to a second end. Thefirst end can have an opening 215 disposed therein for receiving theelongate shaft 210 and the second end has a slot 217 disposed thereinthat is transverse to a longitudinal axis of the elongate shaft 210. Theslot 217 receives a pin 219 extending from a front handle 218. Actuationof the front handle 218 shifts the opening 215 disposed in the first endof the shaft clutch 214 off angle to engage and distally translate theelongate shaft 210 as the front handle 218 is actuated towards astationary rear handle 220. The front handle 218 can be rotatable abouta pivot axis 126 (shown in FIG. 1) that is transverse to a longitudinalaxis 222 extending from a proximal end to a distal end of the main body.A shaft spring 223 positioned proximal to the shaft clutch 214 and aboutthe elongate shaft 210 can urge the shaft clutch 214 and front handle218 back to the starting point of the actuation cycle of the tensioner102. The shaft lock 216 can be biased via a distally-located lock spring224 to prevent unwanted distal translation of the elongate shaft 210.The shaft lock 216 can be released by articulating the shaft lock 216proximally if the tension on the cord 108 needs to be released, such asonce the cord 108 is secured within the implant 106. Additionally oralternatively, a cord nut 232 disposed on proximate a proximal end ofthe cord lock housing 208 can be rotated to adjust the cord tension viaengagement with threading 234 disposed on the proximal end of theelongate shaft 210. In one example, the elongate shaft 210 can beproximally translated from about 30 mm to about 35 mm during eachactuation cycle or stroke of the shaft clutch 214. The tensioner 102 canbe actuated via a single hand of a surgeon, freeing the other hand forperforming other surgical tasks during and adjacent to cord tensioning.

The nose assembly 110 can comprise a piston 226 having a lumen 228extending therethrough for receiving the cord and a load spring 230positionable in contact with an indicator region 120 disposed on thepiston 226. The indicator region 120 of the piston 226 can have a crosssectional diameter than can be greater than or equal to any otherportion of the piston 226. A nose cap can retain the piston 226 and loadspring 230 in the main body 124 of the tensioner 102. The load spring230 can be calibrated so that the position of the indicator region 120of the piston 226 correlates to the load applied to the cord as the cord108 is tensioned and there is a counter pressure applied by the countertensioner 104 to the nose assembly 110. The indicator region 120 can bevisible through a window 122 disposed on the main body 124 of thetensioner 102 having indicia 128 printed adjacent thereto indicative ofcord load at various indicator region positions relative to thetensioner main body 124, as best illustrated in FIG. 1. The piston 226can have a detent 236 disposed in a circumferential outer surface of thepiston 226 proximate a distal end thereof for coupling to the countertensioner 104.

One exemplary embodiment of a counter tensioner 104 according to thepresent disclosure is illustrated in FIGS. 1, 3A, and 3B. The countertensioner 104 can be releasably coupleable to the head of an implant 106at a distal end 304 thereof. The counter tensioner 104 can guide thecord 108 to a port 118 proximate the proximal end 308 thereof. The port118 can allow the cord to be fed through the nose assembly 110 to besecured in the cord lock housing 208 of the cord lock assembly 112. Theport 118 can rigidly, releasably receive the nose assembly 110 of thetensioner 102 via a capture ball disposed in the port 118 for engagingthe decent 236 of the piston 226. The counter tensioner 104 can furthercomprise a lumen 310 disposed therein extending from the distal end 304to the proximal end 308 thereof. The port 118 can be disposed at anangle that is not parallel to a longitudinal axis of the lumen 310. Aset screw (not shown) can be deliverable through the lumen 310 andengageable with the head of the implant to secure the cord therein witha driver (not shown). The counter tensioner 104 can comprise a handle130 that can facilitate translation of the implant 106 relative toanother implant implanted in an adjacent or nearby vertebrae.Accordingly, vertebral translation, cord tensioning, and cord fixationcan be performed in the same surgical step.

The counter tensioner 104 can further comprise an inner sleeve 314 andan outer sleeve 316. The inner sleeve 314 can comprise a plurality ofoutwardly biased arms at a distal end thereof that are engageable withcooperating features disposed on the head of the implant. Advancing theouter sleeve 316 distally over the inner sleeve 314 and at leastpartially over the head of the implant can urge the outwardly biasedarms into secure engagement with cooperating features on the head of theimplant.

Another exemplary embodiment of a counter tensioner 400 according to thepresent disclosure is illustrated in FIGS. 4A-5B. Here, the countertensioner 400 can comprise an inner sleeve 402 and an outer sleeve 404.A distal end of the outer sleeve 404 comprises a fulcrum 406 that canmove from a first position where the fulcrum 406 is parallel to alongitudinal axis of the counter tensioner 400 to a second positionwhere the fulcrum 406 pivots outwardly from the longitudinal axis of thecounter tensioner 400. The inner sleeve 402 can comprise at least oneprojection 408 that can urge the fulcrum 406 outward as the outer sleeve404 passes distally over the inner sleeve 402 and at least partiallyover the head of the implant. The fulcrum 406 serves to change the cordangle, easing local tension on the cord as it is routed up to thetensioner 102 engaged in the port 118. Optionally, a pivoting latch 410can be provided at a proximal end of the inner sleeve 402. The pivotinglatch 410 can be operatively coupled to the counter tensioner 400 sothat the pivoting latch 410 moves downward as the fulcrum moves toward aparallel orientation relative to the longitudinal axis of the countertensioner 400 and upward as the fulcrum pivots outwardly from thelongitudinal axis of the counter tensioner. As a skilled artisan willappreciate in light of the present disclosure, the fulcrum can reducestress applied to the cord during the tensioning process.

FIG. 6 is a flowchart illustrating a method 500 according to anexemplary embodiment. The method 500 can include operations such ascoupling a counter tensioner to an implant at 502; coupling a tensionerto the counter tensioner at 504; routing a cord through the countertensioner and securing the cord in the tensioner at 506; and tensioningthe cord at 508. The method 500 can begin at 502 with a countertensioner, such as counter tensioner 104, being inserted through anincision and coupled to a head of an implant. In an example, the countertensioner 104 includes an inner sleeve (e.g., inner sleeve 314)including biased arms located at a distal end thereof and an outersleeve (e.g., outer sleeve 316). In this example, the biased arms can beengaged with cooperating features on the head of the implant, and theouter sleeve can subsequently be slid distally to lock the biased armsonto the head of the implant. In another example, the counter tensionercan include a threaded feature, a quick connect feature, or the like ata distal end thereof to couple the counter tensioner 104 tocomplementary features disposed on the head of the implant. In yetanother additional or alternative example, the counter tensioner 104 canengage the head of the implant such that the longitudinal axis of theimplant and the longitudinal axis of the counter tensioner are notparallel and the cord can couple the counter tensioner to the implant.

At 504, the method 500 can continue with the tensioner 102 being coupledto the counter tensioner 104. In an example, the tensioner 102 includesa nose assembly 110 including a piston 226 formed from a cylinder with adetent 236 disposed in a circumferential outer surface and proximate adistal end thereof. The detent 236 in the piston 226 can engage acapture ball biased into the port 118.

At 506, the method 500 can continue with guiding a cord from theproximal end of the counter tensioner 104, through the port 118 and alumen 228 disposed in a piston 226 of the nose assembly 110 of thetensioner 102, and securing the cord within a cord lock housing 208 of acord lock assembly 112 disposed at the end of an elongate shaft 210, thecord being secured in an implant 106 in an adjacent or nearby vertebrae.

At 508, the method 500 can continue with tensioning the cord 108 byactuating a front handle 218 of the tensioner 102 to cause a shaftclutch 214 to engage and distally translate the elongate shaft 210 andthe cord 108.

At 510, the method 500 can continue by preventing proximal travel of theelongate shaft 210 at the end of the stroke of the shaft clutch 214 bycausing the shaft lock 216 to engage and prevent return of the elongateshaft 210.

At 512, the method 500 can optionally include translating the implantand underlying vertebrae relative to an implant of an adjacent or nearbyvertebrae. Here, a surgeon can grasp handle 130 to translate the implantcoupled to the counter tensioner 104. The steps of tensioning the cordand translating the vertebrae can be performed simultaneously.

The method can further comprise indicating a load on the cord by theposition of an indicator region of a piston of the nose assemblyrelative to indicia printed adjacent a window in a main body of thetensioner. As the cord is tensioned and counter pressure is applied tothe piston of the nose assembly, the piston depressed the load springand an indicator region of the piston moves in the window disposed inthe main body relative to the printed indicia printed adjacent to thewindow to indicate the load applied to the cord.

Another exemplary embodiment of a cord tensioning system, system 700, isillustrated in FIGS. 7A-7G. The system 700 can comprise a tensioner 702and a counter tensioner 704, which are used in combination formanipulating implants 106 coupleable by a cord 108 (not illustrated inconjunction with this example). The tensioner 702 is designed to enableone-handed operation to apply tension to a cord 108 (similar to thatshown in FIG. 1). The tensioner 702 includes similar structural featuresto tensioner 102 discussed in reference to FIGS. 1-3, and will not befurther described in reference to this example. The counter tensioner704 can be releasably coupleable to a head of an implant 106 at a distalend 714 thereof and can have a port 718 disposed in a proximal end 716thereof. The port 718 can releasably receive the nose assembly of thetensioner 702 (tensioner 102 is interchangeable with tensioner 702). Thecounter tensioner 704 can further be rigidly coupleable to both the headof the implant 106 and the nose assembly, allowing a surgeon to tensionthe cord 108 via the tensioner 702 and translate the implant 106 andunderlying vertebrae relative to another implant implanted in anadjacent or nearby vertebrae via a handle 730 in the same surgical stepand as explained in greater detail below. The remaining discussion ofcounter tensioner 704 focuses on the aspects that differ from examplesdiscussed above.

In this example, the counter tensioner 704 includes a handle 730 withadditional features, such as a lock position 732, an unlock position734, and a lock handle 736. The lock handle 736 is rotatable between thelock position 732 and the unlock position 734. In the unlock position734, the counter tensioner 704 can be inserted over an implant, such asimplant 106 (e.g., a pedicle screw). Once inserted over the pediclescrew, the lock handle 736 can be rotated into the lock position 732 andelements discussed below will lock the counter tensioner 704 to thepedicle screw. Internal workings of the lock mechanism are discussed inreference to FIGS. 7F and 7G below.

Along the length of the counter tensioner 704 extend a pair of lockingextensions 740A, 740B within a pair of locking extension channels 742A,742B. FIGS. 7A-7B only illustrate locking extension 740A and lockingextension channel 742A. In this example, the locking extensions 740A,740B are square elongate members connected at a proximal end to alocking mechanism operated by the lock handle 736. In other examples,the locking extensions 740A, 740B can be cylindrical rods or othercross-sectional profiles. The locking extension channels in this exampleare open square (or rectangular) channels, designed to fit the lockingextensions 740A, 740B. Moving to the distal end 714 of the countertensioner 704, the locking extension 740A engages one of the pivot locks750A (pivot lock 750B is disposed on the opposite side, and shown inFIGS. 7D and 7E). In other examples, the locking extension channels canbe a different cross sectional shape and/or be internal to the countertensioner 704. FIGS. 7A and 7B also illustrate a cord fulcrum 706, acord channel 708, and a cord guide 710A (cord guide 710B is an openingon the opposing side of the distal end 714 not illustrated in thisexample). The cord guide 710A allows the cord to exit the countertensioner 704 and pedicle screw. The cord guides 710A, 710B are designedto complement the U-shaped pedicle screw head adapted to receive thecord. The cord fulcrum 706 includes an enlarged radius area to smoothdirectional change in the cord from a first direction essentiallytransverse to a longitudinal axis of the counter tensioner 704 to asecond direction essentially parallel the longitudinal axis (see FIG. 1,the cord fulcrum 706 operates in a manner similar to fulcrum 106). Incontrast to fulcrum 106, the cord fulcrum 706 is an integral part of thedistal end 714, and does not include any moving parts (e.g., does notpivot). From the cord fulcrum 706, the cord extents proximally along thecord channel 708 until entering the cord conduit 720 at the base of thetensioner port 718, which is more clearly illustrated in FIG. 7G. Thecord channel 708, in this example, is a semi-circular recess in theelongate portion of the counter tensioner 704.

FIG. 7C is a close-up perspective view of the distal end 714 of thecounter tensioner 704. A number of the structures discussed above areshown in additional detail, including the cord fulcrum 706, the cordchannel 708, the cord guide 710A, a distal end of the locking extension740A, the locking extension channel 742A, and the pivot lock 750A. FIG.7C illustrates the counter tensioner 704 in an unlocked position. Thecord fulcrum 706 in particular is shown in greater detail, in thisfigure it is easier to make out the radius created by the cord fulcrum706. The enlarged radius provides a smoother transition for the cordcoming out of the cord guide 710A and proceeding up along the cordchannel 708.

FIGS. 7D and 7E provide cross sectional views of the distal end 714 ofthe counter tensioner 704 in an unlocked and locked state, respectively.The cross sections provide a detailed view of both sides of the countertensioner 704. For example, both locking extensions 740A, 740B are shownextending down opposite sides of the counter tensioner 704 andterminating in extension wedges 744A, 744B. The extension wedges 744A,744B tapper the locking extensions 740A, 704B down to a thin edge alongthe distal most portion. In this example, the extension wedges 744A,744B tapper at approximately 60 degrees, but other tappers can be used.The extension wedges 744A, 744B engage with lock wedges 756A, 756B,respectively. The lock wedges 756A, 756B in this example tapper at acorresponding amount to produce an essentially opposing structure to theextension wedges 74A 744B. In some examples, the ramp (tapper) angle onthe lock wedges 756A, 756B is slightly greater or slightly less than theextension wedges 756A, 756B to reduce friction between the surfaces. Thelocking mechanism within the handle 730 operates to linearly translatethe locking extensions 740A, 740B from the unlocked position shown inFIG. 7D to a locked position shown in FIG. 7E. Upon translation, theextension wedges 744A, 744B engage the lock wedges 756A, 756B and causethe pivot locks 750A, 750B to rotate about pivots 754A, 754B to shiftlocking pins 752A, 752B into recesses within a head of the pediclescrew. The pivot locks 750A, 750B are biased into an unlocked positionby springs (not shown for clarity) disposed within spring recesses 758A,758B with the springs held in place by spring pins 764A, 764B. Thelocking pins 752A, 752B operate to secure the counter tensioner 704 onthe pedicle screw head when pivoted into the locked position (FIG. 7E).In this example, the locking pins 752A, 752B are cylindrical postsextending radially inward. In other examples, the locking pins 752A,752B can be different cross-sectional shapes, such as square orrectangular. The pedicle screw is also surrounded by the pedicle screwreceptacle 760 that includes pin openings 762A, 762B to receive thelocking pins 752A, 752B, respectively. Pedicle screw receptacle 760receives the longitudinal bore 770, which extends the length of thecounter tensioner 704. The longitudinal bore 770 can allow for insertionof a closure top (e.g., set screw) into the pedicle screw to secure thecord. Finally, FIGS. 7D and 7E illustrate cord guide 710B with opposingcord guide 710A shown in FIG. 7C.

FIGS. 7F and 7G provide cross sectional views of the proximal end 716 ofthe counter tensioner 704. The cross sectional views include details ofthe proximal lock mechanism 780 and interaction with the lock handle736. The proximal lock mechanism 780 operates to linearly translate thelocking extensions 740A, 740B, which in turn shift the pivot locks 750A,750B from an unlocked to locked position as discussed above. Theproximal lock mechanism 780 includes a lock cylinder 782 coupled to thelock handle 736 through two lock cylinder set screws 738A, 738B. Thelock handle 736 rotates the lock cylinder 782, which in turn causestranslation of the locking extension 740A, 740B. The translation isaccomplished, in this example, through interaction between a threadedcylinder 784 and a threaded internal portion of the lock cylinder 782.The threaded cylinder 784 is coupled to the locking extensions 740A,740B through extension coupling pins 786A, 786B. When the lock handle736 is rotated, the lock cylinder 782 rotates with an internal threadedsurface engaging the external threads on the threaded cylinder 784,which is coupled to the locking extensions. As the lock handle 736 andlock cylinder are coupled to the elongate portion of the countertensioner 704, the threaded interaction causes the threaded cylinder 784and locking extensions 740A, 740B to translate in a proximal-distaldirection. Other mechanisms for translating the locking extensions 740A,740B can be utilized without deviating from this basic design, such as acam follower arrangement between the lock cylinder 782 and lockingextensions 740A, 740B.

FIG. 7G also provides illustration of the cord conduit 720 leading tothe tensioner port 718. As discussed above, the cord can be routed outof the cord guide 710A, around the cord fulcrum 706, proximally alongthe cord channel 708, through the cord conduit 720, and into thetensioner 702 through the tensioner port 718.

FIG. 8A is a drawing illustrating a cord tensioning system 800 operatingthrough an auxiliary surgical port 805A, according to variousembodiments of the present disclosure. In this example, the cordtensioning system 800 is illustrated as including a plurality ofsurgical ports 805A, 805B (collectively referenced as surgical port(s)805), a tensioner 702, a counter tensioner 704, and a tensionerextension 810. The cord tensioning system 800 is illustrated inreference to an exemplary spine 860 with spinal implants 850A-850F(collectively or individually referenced as spinal implant(s) 850). Inthis example, the spinal implants 850 are pedicle screws with tulipheads adapted to receive a surgical cord (not illustrated). The exampleillustrated in FIG. 8A is intended to demonstrate, generally, how thecord tensioning system 800 is utilized in reference to a patient'sspine. However, the illustration is not necessarily to scale oranatomically correct, rather it is merely intended to demonstration howthe instruments function in combination and relative relationship.

In general, the cord tensioning system 800 is designed to reducecomplexity and increase the speed of implanting a surgical cord (e.g.,flexible elongate tether) along a deformed portion of a patient's spine.Prior to creation of the cord tensioning system 800 by the presentinventors, implanting a surgical cord involved complex manipulations ofthe surgical cord through several surgical ports positions directly overthe spinal deformity (one or more ports, usually one for every 1 to 3vertebrae), such as surgical port 805B. The cord manipulations involvedsecuring the cord to a pedicle screw, maneuvering it through the bodytowards the next pedicle screw, bring the cord up through the surgicalport, tensioning the cord, securing the cord to the present pediclescrew, pushing the cord back down through the surgical port andrepeating for the next screw. The surgical ports are necessary duringthis procedure to keep CO₂ used to deflate the lung within the bodycavity. Manipulating the cord in and out of the surgical ports is a timeconsuming and challenging part of the surgical procedure.

Utilizing the tensioner extension 810 in combination with an auxiliarysurgical port, such as surgical port 805A, positioned inferior to thespinal deformity, can avoid maneuvering the surgical cord into and outof a surgical port for each and every spinal implant. In the revisedprocedure (detailed further in reference to FIG. 12 below), a surgeonthreads the surgical cord through the tensioner extension and utilizesthe extension to position the surgical cord into each spinal implant andalso tension the cord between spinal implants. The revised procedureavoids the need to thread the cord in and out of a surgical port foreach and every spinal implant in the deformity correction construct.

In this example, the tensioner extension 810 can include a dual coupler820 attached to a proximal end of an elongate extension member 830, aswell as a nose member 840 attached to a distal end of the elongateextension member 830. As illustrated, one of the functions of the dualcoupler 820 is to enable the tensioner 702 to couple to the tensionerextension 810. As discussed below, the dual coupler 820 is also designedto enable connection of a secondary extension to elongate the coretensioning system 800, which allows for the system to operate over alarger deformity construct with minimal additional steps in the surgicalprocedure. The tensioner extension 810 can be in the range of 300 mm to400 mm in length. However, tensioner extensions of different lengths caneasily be produced in accordance with this disclosure.

FIG. 8B is a drawing illustrating a cord tensioning instrument 800including a tensioner extension 810 and secondary extension 870,according to various embodiments of the present disclosure. In thisexample, the cord tensioning instrument 800 is illustrated with theoptional secondary extension 870 coupled between the tensioner 702 andthe tensioner extension 810. The secondary extension 870 can provide asurgeon with extra length to reach the most superior spinal implantneeded to correct the spinal deformity. The secondary extension 870 isdesigned to allow for quick connection and disconnection, so that as thesurgeon moves closer to the auxiliary surgical port, the overall lengthof the cord tensioning instrument 800 can be reduced by removing thesecondary extension 870 from between the tensioner 702 and tensionerextension 810. Addition or removal of the secondary extension 870 can beperformed without re-threading the surgical cord through the tensionerextension 810, which means using it or removing it will not slow downthe overall procedure in any significant way.

As illustrated in FIG. 8B, the dual coupler 820 on the tension extension810 includes structures to enable secure coupling of the secondaryextension 870. In this example, the dual coupler 820 can receive thedistal extension coupler 890 on the distal end of the short elongateextension member 872 portion of the secondary extension 870. Thesecondary extension 870 can also include a proximal tensioner coupler880 affixed to a proximal end of the short elongate extension member872. In this example, the proximal tensioner coupler 880 includessimilar structures as the dual coupler 820 for receiving and securingthe nose portion 710 of the tensioner 702. In this example, the shortelongate extension member 872 can be a flexible elongate member similarin construction to the elongate extension member 830, but a shorterlength. In this example, the secondary extension 870 is in a range of130 mm to 150 mm in length. As noted above, the elongate members can bea coil spring or silicone tube material, among other materials.

FIGS. 9A-9E are drawings illustrating various aspects of a tensionerextension 810, according to various embodiments of the presentdisclosure. The following describes the structural components of thetensioner extension 810 in accordance with the example illustrated inFIGS. 9A-9E together. In this example, the tensioner extension 810includes an elongate extension member 830 between a dual coupler 820 ona proximal end and a distal nose member 840 on the distal end. Theillustrated example depicts the elongate extension member 830 as a coilspring with no spacing along the longitudinal length between coils ofthe coil spring, which allows the construct flexibility and the abilityto carry tension along the length of the device. FIG. 9B illustrates aperspective view of the dual coupler 820. In this view, structures suchas a coupler bore 821, locking slots 822A, 822B (collectively referencedas locking slot(s) 822), a snap ring 823, a ring groove 824, and acompression member 825. The coupler bore 821 is adapted to receive anose assembly 710 of the tensioner 702 or a coupler barrel 875 of thesecondary extension 870 when the secondary extension 870 is in use.Within the coupler bore 821 is a ring groove 824 with a snap ring 823disposed within a portion of the ring groove 824. The ring groove 824 isa recess extending around an inner circumference of the coupler bore821. The snap ring 823 is partially recessed within the ring groove 824,with a rounded or crowned (opposing angles meeting at a raised ridge)surface extending radially into the coupler bore 821. The snap ring 823only extends partially around the circumference of the ring groove 824,which allows the snap ring 823 to elastically deform. Deformation of thesnap ring 823 allows the nose assembly 710 of the tensioner 702 toextend pass the snap ring 823. In some examples, the nose assembly 710includes a depression or recess extending around the outer circumferencethat is captured by the snap ring 823 upon insertion into the couplerbore 821.

In this example, the dual coupler 820 includes two opposing lockingslots 822. The locking slots 822 each include an opening along the outeredge of the dual coupler 820. From the opening, each locking slotincludes a P-shaped cut-out extending along a sidewall of the dualcoupler 820 (angling around a small portion of the sidewall). TheP-shaped cut-out is shaped to receive a locking pin extending from acoupler portion of the secondary extension 870 (illustrated in FIGS.10A-10F). The locking slots 822 operate in conjunction with the lockingpins to enable a twist-lock coupling between the tensioner extension 810and the secondary extension 870. The twist-lock operation and structureof the locking slots 822 ensures that the secondary extension remainssecurely attached to the tensioner extension 810 during use, but alsoenables quick disconnection when desired.

FIG. 9C is a perspective view of an example distal nose member 840. Inthis example, the distal nose member 840 includes structures such as anose bore 841, a nose chaffer 842, a tapered body section 843, and anose compression member 844. The nose bore 841 extends from the distalmost end through to a lumen extending the length of the elongateextension member 830. Around the outer edge of the nose bore 841 is anose chaffer 842, which operates to reduce any friction or wear on thesurgical cord exiting the tensioner extension 810. The tapered bodysection 843 extends proximally away from the distal end ramping up tothe transition into the nose compression member 844 that couples thedistal nose member 840 to the elongate extension member 830.

FIG. 9D is a cross-sectional view of the dual coupler 820 connected tothe elongate extension member 830. The cross-sectional view provides amore detailed view of the snap ring 823 and ring groove 824, as well asa cord guide 826. The cord guide 826 operates to guide the surgical cordsmoothly from the tensioner 702 into the elongate extension member 830.

FIG. 9E is a cross-sectional view of the distal nose member 840connected to the elongate extension member 830. The cross-sectional viewdetails the nose bore 841, the nose chaffer 842, and a nose cord guide845. The nose cord guide 845 assists in transitioning the surgical cordout of the elongate extension member 830 into the distal nose member840.

FIGS. 10A-10F are drawings illustrating various aspects of the secondarytensioner extension 870, according to various embodiments of the presentdisclosure. In this example, the secondary tensioner extension 870 (alsoreferenced simply as the secondary extension 870) includes a secondaryextension tensioner coupler 871 coupled to a proximal end of a shortelongate extension member 872 as well as an extension coupler 873capping a distal end of the short elongate extension member 872. Thetension coupler 871 includes a snap ring and ring groove comparable tothose discussed above in reference to dual coupler 820 for securing thenose assembly 710 of the tensioner 702 (see FIGS. 10D and 10E).

The secondary extension 870 includes extension coupler 873 for securelyconnecting the secondary extension 870 to the tensioner extension 810.The extension coupler 873 includes locking pins 874A and 874B(collectively referenced as locking pins 874) extending radially awayfrom a coupler barrel 875. As discussed above, the locking pins 874A,874B interact with locking slots 822 to enable a twist-lock operate tosecure the secondary extension 870 to the tensioner extension 810. Thelocking mechanism can also include a bias cylinder 876, which can bespring loaded or otherwise biased towards the locking pins 874 to assistin securing the secondary extension 870. A spring recess 878 isillustrated in FIG. 10F, but no spring or biasing mechanism is shownwithin the recess for clarity. The coupler barrel 875 can extend fromjust proximal of the locking pins 874 to a distal end of the secondaryextension 870. The coupler barrel 875 can include a chaffered distalradial edge to ease insertion into the dual coupler 820 as well as tosmooth the surgical cord transition on the inner edge. The extensioncoupler 873 also includes a extension coupler compression member 877.

FIGS. 11A-11B are drawings illustrating the connection between thetensioner extension 810 and a secondary tensioner extension 870,according to various embodiments of the present disclosure. In thisexample, the dual coupler 820 is illustrated as receiving the extensioncoupler 873, with the locking pins 874 engaged in the P-shaped portionof the locking slots 822. The cross-sectional view illustrates thecoupler barrel 875 engaging the snap ring 823 that is disposed in thering groove 824. In certain examples, both the coupler barrel 875 andthe nose assembly 710 include a detent running around the outercircumference and adapted to engage the snap ring 823 upon insertion.

FIG. 12 is a flowchart illustrating surgical procedure 1200 fortensioning a surgical cord utilizing tensioner 702, tensioner extension810, and optionally a secondary extension 870, according to variousembodiments of the present disclosure. In this example, the surgicalprocedure 1200 can include operations such as: securing a cord in a1^(st) spinal implant at 1202, inserting an auxiliary surgical port at1204, working the cord from the 1^(st) spinal implant to the auxiliarysurgical port at 1206, threading the cord through a tensioner extensionat 1208, optionally coupling a secondary extension and threading thecord at 1210, coupling a tensioner to the cord tensioning instrument at1212, positioning instrument adjacent a 2^(nd) spinal implant at 1214,tensioning the cord at 1216, securing the cord in the 2^(nd) spinalimplant at 1218, and repeating the positioning and tensioning processfor all remaining spinal implants at 1220. In the following discussion,the core tensioning instrument discussed can include the tensioner 702,the tensioner extension 810, and optionally the secondary extension 870.Further, throughout the disclosure the terms tether and cord are used torefer to a flexible, optionally elastic, surgical cord extendablebetween spinal implants, such as pedicle screws.

In this example, the surgical procedure 1200 can begin at 1202 with asurgeon working through a first surgical port, such as surgical port805B, to secure a first end of a surgical cord to a 1^(st) spinalimplant. The 1^(st) spinal implant in this example is the most superiorspinal implant being used to correct the spinal deformity. Otherexamples may include working in an opposite direction and include use ofan auxiliary surgical port that enters the patient superior to thespinal deformity. However, in the present example, an auxiliary surgicalport, such as surgical port 805A, enters the patient inferior to thespinal deformity, such as in the area of the navel or a lateral positionin the abdomen. The surgical procedure 1200 can continue at 1204 withinsertion of an auxiliary surgical port, such as surgical port 805A.Additionally, while the surgical procedure 1200 is discussed utilizingsurgical ports that operate to provide access and seal the body cavity,the surgical procedure could potentially be performed using moretraditional surgical retractors. Accordingly, the type of surgical portor retractor is not material to the described operations involving thecord tensioning instrument 800. However, where surgical ports asdescribed are necessary, such as to retain CO₂ within the body cavity,the cord tensioning instrument 800 further enhances a surgeon's abilityto perform the required steps.

At 1206, the surgical procedure 1200 can continue with the surgeonworking/maneuvering the cord from the 1^(st) spinal implant up throughthe auxiliary surgical port. At 1208, the surgical procedure 1200 cancontinue with the cord being threaded through a cord tensioninginstrument, such as cord tensioning instrument 800 (previouslyreferenced as cord tensioning system 800). At this stage of surgicalprocedure 1200, the cord tensioning instrument 800 can include at leastthe tensioner extension 810. At 1210, the surgical procedure 1200 canoptionally include coupling a secondary extension, such as secondaryextension 870, to the cord tensioning instrument 800. In an example,coupling the secondary extension 870 involves threading the secondaryextension over the cord, inserting the coupling barrel 875 into the dualcoupler 820, and locking the locking pins 874 into the locking slots822. Once, the desired extension length is configured for the coretensioning instrument 800, the surgical procedure 1200 can continue at1212 by coupling tensioner 702 onto the cord tensioning instrument 800.Note, in some examples, the surgeon may delay coupling the tensioner 702to the core tensioning instrument 800 if maneuvering the cord within thepatient is easier without the tensioner 702 attached. The tensioner 702can be attached and detached as needed to facilitate the procedure.

At 1214, the surgical procedure 1200 can continue with the surgeonpositioning instruments, such as a distal end of the cord tensioninginstrument 800 and a counter tensioner 704 adjacent a 2^(nd) spinalimplant. In this step, the distal nose member 840 of the tensionerextension 810 can be used to insert the cord into the 2^(nd) spinalimplant and then be positioned adjacent the 2^(nd) spinal implant fortensioning the cord. The counter tensioning 704 can assist inpositioning the cord and is also used to insert a set screw later in theprocedure.

At 1216, the surgical procedure 1200 can continue with the surgeon usingthe cord tensioning instrument 800 to tension the cord between the1^(st) and 2^(nd) spinal implant. Tensioning occurs through the surgeonarticulating the tensioner 702, which pulls on the cord, while countertension is carried through the tensioner extension 810 to the side ofthe 2^(nd) spinal implant (see FIG. 8A). Once the desired amount oftension has been applied, the surgical procedure 1200 can continue at1218 with the surgeon inserting a set screw into the 2^(nd) spinalimplant to secure the cord. In this example, the counter tensioner 704can be utilized to deliver the set screw through a surgical port intothe spinal implant.

Finally, the surgical procedure 1200 can continue at 1220 with thesurgical team shifting the instruments to the next spinal implant, suchas a 3^(rd) spinal implant, and repeating operations 1214 to 1218. Oneof the benefits of utilizing the cord tensioning instrument 800 involvesnot having to repeatedly maneuver the cord in and out of a surgical portfor each spinal implant. Rather, with surgical procedure 1200 the cordis only maneuvered up through the auxiliary surgical port once. In someexamples, tensioning and securing the cord to the final spinal implant,such as spinal implant 850F, may be performed using the countertensioner 704 in combination with tensioner 702 with the cord threadedup through a surgical port positioned above the spinal implant.

Each of the above non-limiting examples can stand on its own, or can becombined in various permutations or combinations with one or more of theother examples.

Additional examples of the presently described method, system, andinstrument examples include the following, non-limiting configurations.Each of the following non-limiting examples may stand on its own, or maybe combined in any permutation or combination with any one or more ofthe other examples provided below or throughout the present disclosure.

Example 1 describes subject matter including a tensioner extensioninstrument. The tensioner extension instrument can include an elongatebody, a dual coupler, and a nose member. The elongate body can comprisea flexible cylindrical member adapted to carry tension along alongitudinal axis of the elongate body. The flexible cylindrical membercan be sized to receive a surgical cord through a lumen within theflexible cylindrical member. The dual coupler can be disposed on aproximal end of the elongate body and include a bore for receiving anose portion of a tensioner and guiding the surgical cord into thetensioner. The nose member can be disposed on a distal end of theelongate body, and be adapted to discharge the surgical cord from theelongate body.

In example 2, the subject matter of example 1 can include the dualcoupler having an internal snap ring disposed within the bore andadapted to engage a groove in the nose portion of the tensioner.

In example 3, the subject matter of example 2 can include the internalsnap ring being disposed within a ring groove running around an internalcircumference of the bore.

In example 4, the subject matter of example 3 can include the snap ringhaving a first end and a second end that form a gap within the ringgroove enabling the snap ring to deform radially within the ring grooveupon insertion of the nose portion of the tensioner.

In example 5, the subject matter of any one of examples 1 to 4 caninclude each of the nose member and the dual coupler including acompression member connecting the nose member and the dual coupler toopposite ends of the elongate body.

In example 6, the subject matter of any one examples 1 to 5 can includethe dual coupler having a cord guide abutting a portion of the elongatebody proximal to the compression member, the cord guide including areduced diameter in comparison to the bore and adapted to guide the cordinto the tensioner.

In example 7, the subject matter of any one of examples 1 to 6 caninclude the elongate body being a helical spring structure.

In example 8, the subject matter of example 7 can include the helicalspring structure being a tension spring with unloaded coils that abuteach other to allow the spring structure to carry a compression forcecreated by the tension carried along the longitudinal axis withoutfurther compression of the elongate body.

In example 9, the subject matter of any one of examples 1 to 7 caninclude the elongate body being a flexible tubing material. In certainadditional examples, the flexible tubing material can be silicone.

In example 10, the subject matter of any one of examples 1 to 9 caninclude the dual coupler having a locking slot adapted to receive a lockpin extending radially from a coupler barrel on a distal end of asecondary tensioner extension, where the secondary tensioner extensionis adapted to add to the overall length of the tensioner extensioninstrument.

Example 11 describes subject matter including a system for positioningand tensioning a surgical cord. The system can include a tensioner and atensioner extension. The tensioner can be adapted to apply a tensioningforce to the surgical cord. The tensioner can comprise a nose portionincluding a cylindrical barrel with a central lumen to receive thesurgical cord into the tensioner. The tensioner extension can be adaptedto extend between the nose portion of the tensioner and a spinal implantadapted to receive the surgical cord. The tensioner extension caninclude an elongate body, a dual coupler, and a nose member. Theelongate body can include a flexible cylindrical member to carry tensionalong a length of the elongate body, where the flexible cylindricalmember is sized to receive a surgical cord through a lumen extending thelength of the elongate body. The dual coupler can be disposed on aproximal end of the elongate body. The dual coupler can include a borefor receiving the nose portion of the tensioner and guiding the surgicalcord into the tensioner. The nose member can be disposed on a distal endof the elongate body, and be adapted to discharge the surgical cord fromthe elongate body.

In example 12, the subject matter of example 11 can include the nosemember being further adapted to abut a spinal implant upon tensioning ofthe surgical code through the tensioner extension.

In example 13, the subject matter of any one of examples 11 or 12 caninclude a secondary extension disposed between the tensioner extensionand the tensioner to increase an overall length of the system.

In example 14, the subject matter of example 13 can include thesecondary extension having an extension coupler, a tensioner coupler,and a short elongate body. The extension coupler can be adapted tosecurely couple to the dual coupler on the tensioner extension. Thetensioner coupler can be adapted to receive the nose portion oftensioner. The short elongate body can include a flexible cylindricalmember to carry tension along a length of the short elongate body, wherethe short elongate body can be positioned between the extension couplerand the tensioner coupler.

In example 15, the subject matter of example 14 can include thetensioner coupler having an internal snap ring disposed within a secondbore that receives the nose portion, where the snap ring can be adaptedto engage a groove in the nose portion of the tensioner.

In example 16, the subject matter of example 15 can include the internalsnap ring being disposed within a ring groove running around an internalcircumference of the second bore.

In example 17, the subject matter of example 16 can include the snapring having a first end and a second end that form a gap within the ringgroove enabling the snap ring to deform radially within the ring grooveupon insertion of the nose portion of the tensioner.

In example 18, the subject matter of example 14 can include theextension coupler having a barrel and a locking pin extending radiallyoutward from the barrel.

In example 19, the subject matter of example 18 can include the dualcoupler having a locking slot adapted to receive the locking pin. Thelocking slot can include a P-shape with a lock position radially offsetfrom an entry opening.

In example 20, the subject matter of example 19 can include theextension coupler having a bias cylinder adapted to abut a proximal endof the dual coupler to bias the locking pin into the lock position ofthe locking slot.

Example 21 describes subject matter including a method for positioningand tensioning a surgical cord between at least two spinal implants. Inthis example, the method can include a series of actions using theinstrument or systems discussed in examples 1 to 20. A first action caninclude maneuvering a proximal end of the surgical cord from a firstspinal implant to an auxiliary surgical port disposed through anincision inferior to a spinal deformity to be corrected by the surgicalcord and spinal implants. A second action can include threading thesurgical cord into a tensioning system including a tensioner and atensioner extension, the tensioner extension including a flexibleelongate body and a distal nose member. A third action can includemaneuvering the flexible elongate body along a length of the surgicalcord until the distal nose member is adjacent a second spinal implant,while a proximal end of the tensioner extension and the tensioner remainoutside the auxiliary surgical port. A fourth action can includepositioning the surgical cord into the second spinal implant. A fifthaction can include tensioning the surgical cord between the first spinalimplant and the second spinal implant by manipulating the tensionerdisposed on the proximal end of the tensioner extension.

In example 22, the subject matter of example 21 can include anadditional action comprising securing the surgical cord in the secondspinal implant by inserting a set screw into the second spinal implantwhile maintaining tension on the surgical cord.

In example 23, the subject matter of example 22 can include securing thesurgical cord by passing the set screw through an instrument extendingthrough a first surgical port adjacent the spinal deformity.

In example 24, the subject matter of any one of examples 21 to 23 caninclude additional an action comprising maneuvering the flexibleelongate body until the distal nose member is adjacent a third spinalimplant, while the proximal end of the tensioner extension and thetensioner remain outside the auxiliary surgical port.

In example 25, the subject matter of example 24 can include maneuveringthe flexible elongate body adjacent the third spinal implant andpositioning a portion of the surgical cord in a body portion of thethird spinal implant.

In example 26, the subject matter of example 25 can include positioninga counter tensioner instrument over the third spinal implant, thecounter tensioner extending through a first surgical port or secondsurgical port adjacent the spinal deformity.

In example 27, the subject matter of any one of examples 21 to 26 caninclude an additional action comprising attaching a secondary extensionbetween the tensioner and the tensioner extension prior to threading thesurgical cord into the tensioning system.

In example 28, the subject matter of example 27 can include, aftersecuring the surgical cord to the second spinal implant, detaching thesecondary extension from between the tensioner and the tensionerextension, and attaching the tensioner directly to the tensionerextension.

In example 29, the subject matter of example 28 can include anadditional action comprising maneuvering the flexible elongate body ofthe tensioner extension until the distal nose member is adjacent a thirdspinal implant, while the proximal end of the tensioner extension andthe tensioner remain outside the auxiliary surgical port.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b) at the time of filing this application, toallow the reader to quickly ascertain the nature of the technicaldisclosure. It is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Also, inthe above Detailed Description, various features may be grouped togetherto streamline the disclosure. This should not be interpreted asintending that an unclaimed disclosed feature is essential to any claim.Rather, inventive subject matter may lie in less than all features of aparticular disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description as examples or embodiments,with each claim standing on its own as a separate embodiment, and it iscontemplated that such embodiments can be combined with each other invarious combinations or permutations. The scope of the invention shouldbe determined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

The claimed invention includes:
 1. A tensioner extension instrumentconfigured to implant a surgical cord into a plurality of bone screwimplants, the tensioner extension instrument comprising: an elongatebody comprising a flexible cylindrical member adapted to carry tensionalong a longitudinal axis of the elongate body, the flexible cylindricalmember sized to receive the surgical cord through a lumen within theflexible cylindrical member and expel the surgical cord for implantationinto one or more of the plurality of bone screw implants; a dual couplerdisposed on a proximal end of the elongate body, the dual couplerincluding a bore for receiving a nose portion of a tensioner and guidingthe surgical cord into the tensioner; and a nose member disposed on adistal end of the elongate body, the nose member adapted to dischargethe surgical cord from the elongate body, wherein the dual couplerincludes an internal snap ring disposed within the bore and adapted toengage a groove in the nose portion of the tensioner.
 2. The tensionerextension instrument of claim 1, wherein the internal snap ring isdisposed within a ring groove running around an internal circumferenceof the bore.
 3. The tensioner extension instrument of claim 2, whereinthe snap ring includes a first end and a second end that form a gapwithin the ring groove enabling the snap ring to deform radially withinthe ring groove upon insertion of the nose portion of the tensioner. 4.The tensioner extension instrument of claim 1, wherein each of the nosemember and the dual coupler include a compression member connecting thenose member and the dual coupler to opposite ends of the elongate body.5. The tensioner extension instrument of claim 4, wherein the dualcoupler includes a cord guide abutting a portion of the elongate bodyproximal to the compression member, the cord guide including a reduceddiameter in comparison to the bore and adapted to guide the cord intothe tensioner.
 6. The tensioner extension instrument of claim 1, whereinthe elongate body is a helical spring structure.
 7. The tensionerextension instrument of claim 6, wherein the helical spring structure isa tension spring with unloaded coils that abut each other to allow thespring structure to carry a compression force created by the tensioncarried along the longitudinal axis without further compression of theelongate body.
 8. The tensioner extension instrument of claim 1, whereinthe elongate body is a flexible tubing material.
 9. The tensionerextension instrument of claim 1, wherein the dual coupler includes alocking slot adapted to receive a lock pin extending radially from acoupler barrel on a distal end of a secondary tensioner extension, thesecondary tensioner extension adapted to add to an overall length of thetensioner extension instrument.
 10. A system for positioning andtensioning a surgical cord between a plurality of spinal implants, thesystem comprising: a tensioner adapted to apply a tensioning force tothe surgical cord to be secured between the plurality of spinalimplants, the tensioner comprising a nose portion including acylindrical barrel with a central lumen to receive the surgical cordinto the tensioner; and a tensioner extension adapted to extend betweenthe nose portion of the tensioner and a spinal implant adapted toreceive the surgical cord, the tensioner extension comprising: anelongate body comprising a flexible cylindrical member to carry tensionalong a length of the elongate body, the flexible cylindrical membersized to receive the surgical cord through a lumen extending the lengthof the elongate body; a dual coupler disposed on a proximal end of theelongate body, the dual coupler including a bore for receiving the noseportion of the tensioner and guiding the surgical cord into thetensioner; and a nose member disposed on a distal end of the elongatebody, the nose member adapted to discharge the surgical cord from theelongate body into a spinal implant of the plurality of spinal implants.11. The system of claim 10, wherein the nose member is further adaptedto abut the spinal implant upon tensioning of the surgical cord throughthe tensioner extension.
 12. The system of claim 10, further comprisinga secondary extension disposed between the tensioner extension and thetensioner to increase an overall length of the system.
 13. The system ofclaim 12, wherein the secondary extension includes: an extension coupleradapted to securely couple to the dual coupler on the tensionerextension; a tensioner coupler adapted to receive the nose portion oftensioner; and a short elongate body comprising a flexible cylindricalmember to carry tension along a length of the short elongate body, theshort elongate body positioned between the extension coupler and thetensioner coupler.
 14. The system of claim 13, wherein the tensionercoupler includes an internal snap ring disposed within a second borethat receives the nose portion, the snap ring is adapted to engage agroove in the nose portion of the tensioner.
 15. The system of claim 14,wherein the internal snap ring is disposed within a ring groove runningaround an internal circumference of the second bore.
 16. The system ofclaim 15, wherein the snap ring includes a first end and a second endthat form a gap within the ring groove enabling the snap ring to deformradially within the ring groove upon insertion of the nose portion ofthe tensioner.
 17. The system of claim 13, wherein the dual couplerincludes a locking slot adapted to receive a locking pin extendingradially outward from a barrel of the extension coupler, the lockingslot including a P-shape with a lock position radially offset from anentry opening.
 18. The system of claim 17, wherein the extension couplerincludes a bias cylinder adapted to abut a proximal end of the dualcoupler to bias the locking pin into the lock position of the lockingslot.
 19. A method for positioning and tensioning a surgical cord inspinal implants, the method comprising: maneuvering a proximal end ofthe surgical cord from a first spinal implant to an auxiliary surgicalport disposed through an incision inferior to a spinal deformity to becorrected by the surgical cord and spinal implants; threading thesurgical cord into a tensioning system including a tensioner and atensioner extension, the tensioner extension including a flexibleelongate body and a distal nose member; maneuvering the flexibleelongate body along a length of the surgical cord until the distal nosemember is adjacent a second spinal implant, while a proximal end of thetensioner extension and the tensioner remain outside the auxiliarysurgical port; positioning the surgical cord into the second spinalimplant; and tensioning the surgical cord between the first spinalimplant and the second spinal implant by manipulating the tensionerdisposed on the proximal end of the tensioner extension.
 20. A tensionerextension instrument for positioning and tensioning a surgical cordbetween spinal implants, the tensioner extension comprising: an elongatebody comprising a flexible cylindrical member adapted to carry tensionalong a longitudinal axis of the elongate body, the flexible cylindricalmember sized to receive a surgical cord through a lumen within theflexible cylindrical member; a dual coupler disposed on a proximal endof the elongate body, the dual coupler including a bore for receiving anose portion of a tensioner and guiding the surgical cord into thetensioner; and a nose member disposed on a distal end of the elongatebody, the nose member adapted to discharge the surgical cord from theelongate body into a head of a spinal implant, wherein the dual couplerincludes a cord guide abutting a portion of the elongate body proximalto a compression member, the cord guide including a reduced diameter incomparison to the bore and adapted to guide the cord into the tensioner.21. A tensioner extension instrument comprising: an elongate bodycomprising a flexible cylindrical member adapted to carry tension alonga longitudinal axis of the elongate body, the flexible cylindricalmember sized to receive a surgical cord through a lumen within theflexible cylindrical member; a dual coupler disposed on a proximal endof the elongate body, the dual coupler including a bore for receiving anose portion of a tensioner and guiding the surgical cord into thetensioner; and a nose member disposed on a distal end of the elongatebody, the nose member adapted to discharge the surgical cord from theelongate body, wherein the dual coupler includes a locking slot adaptedto receive a lock pin extending radially from a coupler barrel on adistal end of a secondary tensioner extension; the secondary tensionerextension adapted to add to an overall length of the tensioner extensioninstrument.